HIV infected (HIV+) heavy drinkers are at risk for cardiovascular diseases (CVD) via myriad pathways. Heavy alcohol use causes microbial translocation (MT) and inflammation. Additionally, alcohol-related changes in the GI tract microbiome?termed dysbiosis?are central to this pro-inflammatory cascade and could serve as novel therapeutic targets for reducing CVD risk among HIV+ heavy drinkers. Alcohol-associated dysbiosis is characterized by a loss of gut bacterial biodiversity, a reduction in ?beneficial? bacteria, and/or an expansion of harmful or ?pro-inflammatory? bacteria (e.g., those which produce trimethylamine N-oxide (TMAO), a metabolite associated with increased CVD risk). While murine models show alcohol associated dysbiosis was attenuated by probiotics even in the presence of continued alcohol consumption, there remains insufficient knowledge to identify a therapeutic target in humans for two reasons: 1) most studies involve murine models; and 2) scant human studies have small sample sizes with few HIV+ participants, and lack longitudinal assessment of alcohol intake, inflammation, and CVD risk in relation to the GI microbiome. This application addresses these gaps. We hypothesize that alcohol-associated dysbiosis will: (1) be greater in HIV+ very heavy drinkers (AUDIT score?20) vs. heavy drinkers (AUDIT<20); (2) increase biomarker levels of intestinal permeability (e.g., intestinal fatty acid binding protein (IFABP), MT (e.g., endotoxin), inflammation (interleukin 6) and TMAO; and (3) increase serum biomarkers for and alter echocardiographic (Echo) measures of cardiac function (N-terminal pro Brain Naturetic Peptide, NT pro-BNP, and left ventricular ejection fraction, LVEF, respectively). To test these hypotheses, we will enroll 200 HIV+ participants from St. PETER HIV, a funded RCT using pharmacotherapy to reduce alcohol use, smoking, inflammation, and CVD risk. This application, Alcohol-associated CVD and Microbiome Evaluation Study (ACME HIV 1/2) leverages existing resources of St. PETER HIV: participant recruitment, measures of alcohol consumption, biospecimen and biomarker collection; expertise in alcohol, HIV, CVD, and microbial genomics. New data include: fecal samples to characterize the GI microbiome, serum biomarkers, and echo measures. In response to RFA-AA-17-014, we will partner with the Southern HIV & Alcohol Research Consortium (SHARC, ACME HIV 2/2) to corroborate our findings in Aims 1 and 2 and to conduct combined cross-cohort analyses. We will complete the following SPECIFIC AIMS among HIV+ heavy drinkers: AIM 1: To assess longitudinal qualitative and quantitative changes in the gut microbiome (dysbiosis) associated with very heavy alcohol consumption. AIM 2: To determine the effect of dysbiosis on intestinal permeability, MT, inflammation, and TMAO levels. AIM 3: To investigate the impact of dysbiosis on biomarkers for and echo measures of cardiac structure and function. Completion of these aims will lay groundwork for an intervention targeting alcohol-associated dysbiosis, which could profoundly reduce inflammation and favorably impact CVD risk among HIV+ heavy drinkers.